大漠飞泉
幼苗
共回答了20个问题采纳率:85% 举报
由题意可知
f(x)=向量OA×向量OB+m
=2sin平方x-2√3sinxcosx+1+m
=1-cos2x-√3sin2x+1+m
=-2sin(2x+π/6)+2+m
1.) 单增区间2x+π/6∈[2kπ+π/2,2kπ+3π/2]
x∈[kπ+π/6,kπ+2π/3]
2.) 即当x∈[π/2,π] 2x+π/6∈[7π/6,13π/6]
f(x)max=2+m+2=m+4 f(x)min=2×(-1/2)+2+m=m+1
m+4=5 m+1=2
得m=1
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1年前
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